UV treatment device with time delay of water flowing there through

ABSTRACT

A device for degerminating water passing through a sanitary appliance includes a housing  23  through which water can flow, a water outlet  3  and a UV lamp  22  located therein that radiates water flowing through the housing and a filtering device  21  provided in the housing in order to destroy the micro-organisms in the water and/or the filtering device. The energy supply circuit of the UV-lamp is controlled by an electronic control unit  10 , which also controls a valve driver circuit for a magnetic valve  6  located in a fresh water feed pipe. The electronic control unit activates the energy supply circuit when it receives a signal for switching on the UV-lamp. The valve driver circuit is activated after a time delay, ensuring that when the magnetic valve opens letting water flow through the housing to the outlet of the appliance, the UV-lamp has reached its full radiation capacity.

CROSS-REFERENCES TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for sterilizing water flowing througha sanitary appliance, having

a) a housing, which comprises an inlet and an outlet for the water;

b) a UV lamp, which is disposed inside the housing and the radiation ofwhich is directed towards the water flowing through and optionallytowards a filtering apparatus likewise disposed in the housing;

c) a power supply circuit for the UV lamp;

d) a device for producing a switch-on signal for the power supplycircuit of the UV lamp;

e) a solenoid valve, which is situated in the fresh water supply conduitand energized by a valve driver circuit;

f) a control circuit, which is connected to the valve driver circuit ofthe solenoid valve, the power supply circuit for the UV lamp and thedevice for producing a switch-on signal for the UV lamp and is sodesigned that it activates the driver circuit for the solenoid valveonly with a specific time delay after the power supply circuit for theUV lamp;

g) a valve, which is operable by the user, in the fresh water supplyconduit;

h) a pressure sensor situated between the solenoid valve and theuser-operable valve in the fresh water supply conduit.

In recent years the dangers arising in the field of sanitation fromwater contaminated with micro-organisms, in particular bacteria, amoebaeor other monocellular organisms, have become ever clearer. For saidreason, increased importance is being attached to water sterilization.In said connection, there have been reports of experiments to sterilizeflowing water through exposure to UV light, which is of a wavelengthsuitable for killing micro-organisms carried along in the water. Toextend the retention time of said micro-organisms in the region of theUV lamp, an additional filtering apparatus may be used.

2. Technical Field

In the devices known from said experiments, the UV lamp was activatedwhen the water flow is set in operation, e.g. by means of a mechanicalswitch which was mechanically connected to the operating element of thevalve controlling the water flow. However, since the UV lamp uponactivation does not immediately operate at full radiant power, with saidknown devices the sterilizing capacity in the initial phase afterswitching-on was inadequate.

A generic apparatus is known from DE 39 24 350 A1. There, a switch,which via a control circuit 2 activates a UV lamp, is used as a devicefor producing a switch-on signal.

Further devices for sterilizing water with the aid of a UV lamp, whichuse control circuits which activate the valve driver circuit for theinlet valve in the water supply conduit with a time delay compared tothe switching-on of the UV lamp, are known from GB 21 27 177 A, FR 24 14480 A and DE 38 40 276 A.

Upon the occurrence of a “switch-on signal” indicating the request of auser to draw off water, the water flow is not immediately set inoperation. Rather, the control circuit first ensures that the powersupply circuit for the UV lamp is activated. The UV lamp is thereforeignited and comes within a few seconds up to operating temperature,after which its operating state is stabilized and the full luminouscapacity is attained. It is only then, i.e. after a specific time delay,that the control electronics also activate the valve driver circuit forthe additional solenoid valve provided according to the invention; it isonly then that water starts to flow and then encounters inside thehousing of the device a UV lamp which is fully activated and henceoperating at maximum sterilizing capacity.

In the known sterilizing devices, the switch-on signal for the UV lampis produced by means of a switch which is to be separately operated. If,e.g. out of ignorance, said switch is not operated, it is impossible todraw off water.

SUMMARY OF THE INVENTION

The object of the present invention is to refine a device of the typedescribed initially in such a way that automatic activation of the UVlamp is guaranteed in response to a draw-off request by the user, whichis effected in the manner customary with sanitary appliances throughopening of the user-operable valve in the fresh water supply.

Said object is achieved according to the invention in that

i) the solenoid valve is disposed upstream of the valve, which isoperable by the user, in the fresh water supply conduit and that

j) a signal of the pressure sensor ascertaining a pressure drop isutilized as the switch-on signal for the power supply circuit.

The solenoid valve therefore serves simultaneously as part of the devicefor producing a switch-on signal. Said device uses, as a “controlledvariable” indicating the request of the user to start and end adispensing operation, the pressure inside the portion of the fresh watersupply conduit lying between the additional solenoid valve and a valveoperable by the user. By “operable by the user” is meant not only thedirect mechanical operation, e.g. by means of the lever of asingle-lever mixer, by the user. In the context of the presentinvention, a solenoid valve actuated without contact is also “operableby the user”.

The time delay between switching on the power supply circuit for the UVlamp and activating the valve driver circuit for the solenoid valveshould be, say, in the order of magnitude of 0.2 to 3 seconds.

It is advisable to provide the device according to the invention with adisplay, which is activated immediately upon the occurrence of aswitch-on signal. When said display lights up, the user knows that thedevice is working even though the water does not start to flowstraightaway. This prevents irritation on the part of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is described in detail below withreference to the drawings;

FIG. 1 diagrammatically shows a block diagram and the associatedhardware components of a device for sterilizing and filtering waterflowing through a sanitary draw-off appliance.

FIG. 2 shows a housing that contains a filtering apparatus and a UVlamp.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 a sanitary draw-off appliance is diagrammatically illustrated,which in the illustrated embodiment may be thought of a s a bathtuboutlet but may alternatively be part of a complete sanitary appliancecontaining the valve, e.g. a single-lever mixer. Instead of the bathtuboutlet 1, the appliance may alternatively be a shower or the like.

The bathtub outlet 1 is supplied via the fresh water supply conduit 2with water which may contain micro-organisms such as amoebae, bacteriaor similar monocellular organisms. To eliminate the latter, a UV lampand a filtering apparatus (not shown) are integrated inside the bathtuboutlet 1. The UV lamp irradiates the water flowing through as well asthe filtering apparatus and thereby kills the microorganisms which arecarried along by the water and/or retained by the filtering apparatus.Extensively germfree, filtered water therefore passes out of the outletopening 3 of the bathtub outlet 1.

The drawing shows upstream of the bathtub outlet 1 a valve 4 operable bythe user, which may be either a valve operated mechanically through thedirect action of force of the user or a solenoid valve indirectlycontrolled without contact by the user. Further upstream, a pressuresensor 5 is installed in the fresh water supply conduit 2; the freshwater is fed to said pressure sensor by a solenoid valve 6, which is thefirst “element” in the fresh water supply conduit 2.

The circuit arrangement used to operate the previously describedhardware components 1 to 6 is denoted as a whole in the drawing by thereference character 10. The circuit arrangement 10 comprises a powersupply circuit 11 for the UV lamp integrated in the bathtub outlet 1,pressure sensor electronics 12 which process the pressure signalsupplied by the pressure sensor 5, a valve driver circuit 13 whichenergizes the solenoid valve 6, and control electronics 14 which controlthe interaction of the previously mentioned part-components of thecircuit arrangement 10.

The previously described circuit arrangement operates as follows:

The components 5 and 6 lying upstream of the user-operated valve 4inside the fresh water supply conduit 2 serve as a device for producinga switch-on signal in the following manner:

As the initial situation, it is assumed that the valve 4 operated by theuser is closed, i.e. no water is flowing out of the outlet opening 3.The pressure sensor 5 installed in the conduit portion between theupstream solenoid valve 6 and the user-operated valve 4 measures thefull system pressure, which still exists from the preceding workingcycle. When the valve 4 is then opened through the action of the user,the pressure drops dramatically at the pressure sensor 5. The pressuresensor electronics 12 supply a corresponding signal to the controlelectronics 14, which identify the user's “request” to draw off waterfrom the bathtub outlet 1. As the solenoid valve 6 is still closed,initially no water flows out of the outlet opening 3 of the bathtuboutlet 1. However, immediately upon the occurrence of the signal of thepressure sensor 5 indicating the pressure drop, the control electronics14 activate the power supply circuit 11 for the UV lamp situated in thebathtub outlet 1. The UV lamp is therefore ignited at said instant.Immediately after ignition, however, the UV lamp has still not developedits full capacity, which would be sufficient to reliably kill themicro-organisms carried along by the water. The control electronics 14therefore wait for a specific length of time, which empirically isenough to allow the UV lamp to reach its full capacity. It is only aftersaid time delay that the control electronics 14 activate the valvedriver circuit 13, which then energizes the solenoid valve 6 so that thelatter opens. Fresh water then flows through the fresh water supplyconduit 2, past the pressure sensor 5 and through the valve 4, which hasalready been opened by the user, to the bathtub outlet 1 where it mayflow past the UV lamp operating at full capacity, through the filteringapparatus and, having thus been purified, out of the outlet opening 3 ofthe bathtub outlet 1.

When the user requires no more water, he then (again directly orindirectly) closes the valve 4. The pressure sensor 5 senses thepressure rise caused thereby. The corresponding signal is supplied bythe pressure sensor electronics 12 to the control electronics 14. Thelatter then close the solenoid valve 6 by means of a correspondingsignal supplied to the valve driver circuit 13 and moreover—optionallyafter a specific time delay—deactivate the power supply circuit 11 forthe UV lamp situated in the bathtub outlet 1.

FIG. 2 shows a housing 23 that contains a filtering apparatus 21 and aUV lamp 22.

So that the user is not irritated by the delay before the water startsto flow, a display 20 is integrated in the bathtub outlet 1. Saiddisplay lights up, as soon as the UV lamp is activated, and indicates tothe user that the device is working.

What is claimed is:
 1. Device for sterilizing water flowing through asanitary appliance, having: a) a housing, which comprises an inlet andan outlet for the water; b) a UV lamp, which is disposed inside thehousing and the radiation of which is directed towards the water flowingthrough the housing; c) a power supply circuit for the UV lamp; d) adevice for producing a switch-on signal for the power supply circuit ofthe UV lamp; e) a solenoid valve, which is situated in a fresh watersupply conduit leading to the housing and is energized by a valve drivercircuit; f) a control circuit, which is connected to the valve drivercircuit of the solenoid valve, the power supply circuit for the UV lampand the device for producing a switch-on signal and is so designed thatit activates the valve driver circuit only with a specific time delayafter the power supply circuit for the UV lamp is activated; g) a valve,which is operable by the user, in the fresh water supply conduit; h) apressure sensor situated upstream from the UV lamp and between thesolenoid valve and the user-operable valve in the fresh water supplyconduit; wherein i) the solenoid valve is disposed upstream of thevalve, which is operable by the user, in the fresh water supply conduitand j) a signal of the pressure sensor ascertaining a pressure drop isutilized as the switch-on signal of the power supply circuit for the UVamp.
 2. Device according to claim 1, wherein the specific time delay isbetween 0.2 to 3 seconds.
 3. Device according to claim 1, furthercomprising a display, which is activated immediately upon the occurrenceof the switch-on signal.
 4. Device according to claim 1, wherein theradiation of the UV lamp is disposed towards a filtering apparatusdisposed in the housing.
 5. Device for sterilizing water flowing througha sanitary appliance, having a) a housing, which comprises an inlet andan outlet for the water; b) a UV lamp, which is disposed inside thehousing and the radiation of which is directed towards the water flowingthrough the housing; c) a power supply circuit for the UV lamp; d) adevice for producing a switch-on signal for the power supply circuit ofthe UV lamp; e) a solenoid valve, which is situated in a fresh watersupply conduit leading to the housing and is energized by a valve drivercircuit; f) a control circuit, which is connected to the valve drivercircuit of the solenoid valve, the power supply circuit for the UV lampand the device for producing a switch-on signal and is so designed thatit activates the valve driver circuit only with a specific time delayafter the power supply circuit for the UV lamp is activated; g) a valve,which is operable by the user, in the fresh water supply conduit; h) apressure sensor situated upstream from the UV lamp and between thesolenoid valve and the user-operable valve in the fresh water supplyconduit; wherein i) the solenoid valve is disposed upstream of thevalve, which is operable by the user, in the fresh water supply conduit;j) a signal of the pressure sensor ascertaining a pressure drop isutilized as the switch-on signal of the power supply circuit for the UVlamp; and k) the device for producing a switch-on signal for the powersupply circuit of the UV lamp is operationally coupled to the valvewhich is operable by the user and situated in the fresh water supplyconduit.